Computing power is often bundled together or "pooled" to reduce variance in miner income. Individual mining rigs often have to wait for long periods to confirm a block of transactions and receive payment. In a pool, all participating miners get paid every time a participating server solves a block. This payment depends on the amount of work an individual miner contributed to help find that block.[82]
In the beginning, mining with a CPU was the only way to mine bitcoins and was done using the original Satoshi client. In the quest to further secure the network and earn more bitcoins, miners innovated on many fronts and for years now, CPU mining has been relatively futile. You might mine for decades using your laptop without earning a single coin.
Mining is a record-keeping service done through the use of computer processing power.[e] Miners keep the blockchain consistent, complete, and unalterable by repeatedly grouping newly broadcast transactions into a block, which is then broadcast to the network and verified by recipient nodes.[64] Each block contains a SHA-256 cryptographic hash of the previous block,[64] thus linking it to the previous block and giving the blockchain its name.[3]:ch. 7[64]
From a widespread adoption standpoint: for the typical consumer, Bitcoin is technically challenging and cumbersome to use for the inexperienced. They also forfeit the consumer protections afforded by traditional credit and debt cards. Merchants already have incentive to accept it in the form of reduced fees for accepting payments over typical payment processors.

On 1 August 2017, a hard fork of bitcoin was created, known as Bitcoin Cash.[103] Bitcoin Cash has a larger block size limit and had an identical blockchain at the time of fork. On 24 October 2017 another hard fork, Bitcoin Gold, was created. Bitcoin Gold changes the proof-of-work algorithm used in mining, as the developers felt that mining had become too specialized.[104]

Managing mining hardware at home can be hectic, considering electricity costs, hardware maintenance, and the noise/heat generated by dedicated hardware that has to be run in data centers. Because of the high energy costs for running a powerful Bitcoin miner, many operators have chosen to build data centers known as mining farms in locations with cheap electricity. To ease the stress of mining, these operators dedicated to renting out their mining hardware for a service called Bitcoin cloud mining.
In the zero-sum game that cryptocurrency has become, one man’s free money is another man’s headache. In the Mid-Columbia Basin, the latter category includes John Stoll, who oversees Chelan County Public Utility District’s maintenance crews. Stoll regards people like Benny as “rogue operators,” the utility’s term for small players who mine without getting proper permits and equipment upgrades, and whose numbers have soared in the past 12 months. Though only a fraction of the size of their commercial peers, these operators can still overwhelm residential electric grids. In extreme cases, insulation can melt off wires. Transformers will overheat. In one instance last year, the utility says, a miner overloaded a transformer and caused a brush fire.

Transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain. Bitcoin was invented by an unknown person or group of people using the name Satoshi Nakamoto[9] and released as open-source software in 2009.[10] Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies,[11] products, and services. Research produced by the University of Cambridge estimates that in 2017, there were 2.9 to 5.8 million unique users using a cryptocurrency wallet, most of them using bitcoin.[12]